The present invention relates to a protective enclosure that uses a unique support structure for energy management and enclosure reliability based on integral, low modulus ribs that pass through the rigid structural component(s) and preferably originate from one or more soft touch surface components. These ribs provide means for energy management and advantageously can use a common soft touch component material which can also provide enclosure sealing. It also relates to a process for making a protective enclosure having integral, low modulus ribs that pass through the rigid structural component(s), preferably from one or more soft touch surface components that can also provide the enclosure with sealing.
Portable electronic devices and similar types of personal devices, such as cell phones, pagers, personal digital assistants (PDAs), gaming devices, electronic music players, voice recorders, global positioning systems (GPS), digital or conventional film cameras, etc. have become commonplace in today""s society. These personal devices have found utility in all aspects of life including personal and/or professional activities. In most environments, and in industrial and/or outdoor environments in particular, these types of devices are subject to rough handling, occasional impact forces from being dropped or struck, and exposure to liquids, dust, foods, grease, moisture and other contaminants. Thus, in order to continue to operate properly in such environments, these types of devices need a protective enclosure that provides impact resistance, provides a tight seal against liquid or other contaminants, and preferably provides both, to protect sensitive interior components and especially sensitive electronic elements.
The incorporation of so-called soft touch elements into the surface of these devices is well known and provides a range of aesthetic, ergonomic and performance benefits for the device and its use. See for example U.S. Pat. No. 5,563,674 describing the xe2x80x9cergonomicxe2x80x9d issues of soft touch, and specifically anti-slipping characteristics (e.g. to prevent dropping a camera). Similarly, Patent GB 2,348,391 also shows soft touch features in devices and the process of soft touch molding.
There is simultaneously a great interest in making these devices as compact as possible and obtaining the maximum numbers of functions in minimum volumes. Prior art techniques have attempted to solve these problems in several ways. Regarding energy management, commonly referred to as impact resistance or toughness, small, portable electronic products such as Personal Data Assistants (PDAs), and lap top computers, that use glass touch screens or displays are extremely susceptible to damage or failure due to being dropped or accidentally abused. The problem is compounded by the fact that these devices are small, portable, designed to be used everywhere, expensive, and fragile. Normal xe2x80x9cruggedizedxe2x80x9d enclosures provide energy management by packaging the device in a large, bulky box and using shock absorbing inserts or mounts. See for example U.S. Pat. No. 6,144,552 and German Publication DE 19830264. The size and user issues associated with this type of package precludes their use in many instances.
Also, if the opening, closing and/or movable parts of an enclosure are designed to be re-sealable against liquid, dust and the like, they are typically sealed with one or more gaskets made from foam or a deformable material. However, it is well known that these gaskets leak with time and exposure to environmental contamination and cleaning fluids as well as due to differential thermal expansion/contraction. In addition, they also require the use of additional assembly and operation steps to add and seat the gasket(s) itself and, if not attached and seated properly after each opening/closing event, do not always function effectively. In U.S. Pat. No. 5,373,458 it is shown that an overmolded rim of resilient material can provide an enclosure with a seal and a tactile surface but only limited impact resistance can be provided and further resilient gasket pieces are needed.
Accordingly a need exists for a protective enclosure having the benefit of a desirable soft touch surface material for ergonomics and aesthetics that also provides an effective liquid and dust tight seal as well as highly effective and multidirectional pass-through energy management ribs. Preferably combinations of these features are simultaneously provided. Further, it is desirable that the number of parts, assembly steps and hence the cost can be reduced.
Therefore, according to the present invention there is provided a protective enclosure that provides protection and energy management for a sensitive or fragile part or device that can be enclosed, the enclosure comprising one or more rigid structural components and one or more soft touch surface components and having one or more low modulus ribs that are designed appropriately to position and seat the part or device when it is enclosed, such ribs originating from the soft touch surface component and passing through the rigid structural component(s) to provide the protection and energy management for the part or device when it is enclosed. Preferably the soft touch surface component comprises a surface layer over at least a part of one or more of the rigid structural component and more preferably the surface layer sections of the soft touch component have a thickness of from about 0.05 to about 5 millimeters.
In a further embodiment, the protective enclosure has a moveable structural component that (a) opens to provide an opening to receive or remove a device that is protectively enclosed and (b) closes to provide a substantially continuous liquid and dust resistant seal provided by the soft touch component(s). It has also been found that the soft touch component is advantageously prepared from a low modulus, plastic material, preferably a thermoplastic elastomer.
There is also provided a process for producing a protective enclosure part comprising at least one rigid structural component and at least one soft touch surface component and having one or more low modulus ribs for positioning and seating an enclosed part or device, such ribs originating from the soft touch surface component and passing through the rigid structural component(s), the process comprising the steps of (a) first molding the rigid component(s) and (b) subsequently attaching onto the first component the pass through ribs and the soft touch surface. Preferably the pass through ribs and the soft touch surface are molded onto the first rigid component(s) from step (a) by subsequently molding them onto the first component using a two shot molding, insert molding or overmolding process.